Method and system for accomplishing product detection

ABSTRACT

The present invention provides for a vending system wherein a monitoring system verifies that a product ordered by a vending customer is actually delivered through a delivery area to the customer. If the product ordered is unavailable either because of an out of stock situation or a blockage of the delivery path for that product, the present invention allows the customer to request a refund or order a second product. Additionally, the present invention helps to prevent theft of product from the vending system.

This application is a divisional of prior U.S. patent application Ser. No. 09/935,935 filed Aug. 23, 2001, now U.S. Pat. No. 6,732,014, and claims priority U.S. Provisional Patent Application No. 60/271,998, filed Feb. 27, 2001, which is hereby incorporated by reference. This application includes subject matter protected by copyright.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to the vending arts generally and more specifically to vending machine delivery systems for determining whether a product has actually been delivered to the consumer after a customer order.

2. Description of the Prior Art

Currently, vending machines lack the ability to detect and confirm whether an ordered product has been actually delivered to a customer after an ordered vend event by the customer has occurred. Present methods, referred herein as the home switch method, always assume that the ordered product is available for delivery and that the product is successfully delivered upon completing one vend cycle.

However, vending machines often fail to deliver the product after the vend cycle for various reasons, including improper installation of the products by the vendor's sales representative or obstructions in the delivery path. Thus, presently, after paying for the product and a vend cycle occurring, the customer fails to receive the ordered product, resulting in the customer becoming frustrated with the vending company, affecting customer relations and vending sales.

BRIEF SUMMARY OF THE INVENTION

A vending system that verifies the delivery of a ordered product using a product delivery system that sends a product from a first, storage position through a delivery path to a seconds receiving position, a sensing system located along the delivery path that senses when the product passes a sensor during the product transition through the delivery path from the first position to the second position, and a reporting circuitry electronically coupled to the sensing circuitry wherein the reporting circuitry reports to the product delivery system when the product has passed through the sensing system.

Additionally, a vending machine method is provided for determining whether a product is delivered, the method comprising the steps of sending a delivery signal based on a customer ordering event to a product delivery system, monitoring a delivery path that the product travels to reach a product receiving location, and determining if the product was delivered to the receiving space.

The foregoing has outlined some of the more pertinent objects and features of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention as will be described. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the following Detailed Description of the Preferred Embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overview of the methodology utilized in the present invention;

FIG. 2 shows a schematic diagram of the present invention;

FIG. 3A shows the emitter arm portion of the monitoring system;

FIG. 3B shows the detector arm portion of the monitoring system;

FIG. 4 shows the operation of the monitoring system when a customer places an order;

FIG. 5 shows the steady state calibration mode of the monitoring system;

FIG. 6 shows a typical detector arm attached to a vending machine; and

FIG. 7 shows light beam patterns for the emitters in the monitoring system.

DETAILED DESCRIPTION

The present invention is a vending system that verifies that an actual delivery of an ordered product is made. If the actual delivery fails for a set number of delivery attempts, then the customer is offered one or more alternative choices, including without limitation, choosing an alternative product, or a refund.

FIG. 1 is an overview of the methodology utilized in the present invention. The monitoring system is in calibration mode in its normal steady state configuration mode as shown in step 100. Calibration mode is discussed in greater detail in FIG. 5 below. The customer orders a product after placing money in the ordering system by depressing a keypad or similar device in step 102. The vending machine's ordering system sends a customer order event signal in step 103 to the monitoring system informing the sensing/monitoring system that an order event has occurred in step 102. The monitoring system subsequently completes its last calibration cycle in step 104 and transitions from steady state calibration mode to the monitoring cycle in step 106. Upon transitioning, the monitoring system commences its sensing/monitoring cycle by monitoring the product delivery path and sends a ready signal to the product delivery system in step 110. The monitoring cycle is described in more detail in FIG. 4, herein below. After receiving a ready signal from the monitoring system, the product delivery system attempts to deliver a product through the product delivery path in step 120. If the monitoring system senses or detects the product passing through the delivery path in step 125, it reports the delivery event to the ordering system in step 130. Upon receiving the report, the ordering system concludes the transaction with the customer and sends a completion signal to the monitoring system, which returns to steady state calibration mode in step 135, whereupon the monitoring system enters into calibration mode in step 140.

If the monitoring system does not detect a product in the first delivery attempt in step 125 then it will not send a signal to the ordering system after the step 125. The invention allows the delivery system to attempt delivery three times or a preset option. In step 150, if the number of attempted delivery cycles is less than the preset option, then the ordering system thereupon attempts to deliver the product again in step 120. If the attempted delivery cycles equal the preset option, then in step 155 the customer is granted alternatives to purchasing the first ordered product. Step 155 allows the customer to either ask for a refund or make a selection of a second, different product for delivery and step 153 marks the first ordered product as empty.

Step 153 prevents future vend attempts for the first ordered product until the vending machine is visited by a service person. This helps to prevent cheating by a customer if the vending machine reverts to the home switch operation, and helps to prevent further tampering if tampering was the cause of the first vend failure.

If the customer chooses a refund, then the present invention delivers a signal to make a refund, in step 160, whereupon a signal is sent to the monitoring system that the order is complete in step 135 and to the monitoring system to enter into steady state calibration mode in step 140. If the customer chooses a second, different product, then the present invention returns to 120 and the process proceeds as described above, until the operation is complete.

FIG. 2 shows a schematic diagram of the present invention installed in a vending machine 205. In FIG. 2 various products 210 are placed in the vending machine's delivery system 215. Prior to a customer making a purchase, the monitoring system 217 is in calibration mode. When a customer makes an order through the order system 220, the monitoring system completes the calibration mode and enters into its monitoring mode. Thereupon, the ordering system allows for an attempted delivery of the ordered product 210, typically through a helical delivery system 215. When ordered, product 270 is delivered into delivery space 222, falling through the delivery path 225 past monitoring system 217. As it passes the monitoring system, the product momentarily breaks the continuity of the monitoring system's monitoring devices. If the monitoring system utilizes an optical monitoring system, then as the product passes through the monitoring system's light plane 234, be it infrared or otherwise, it momentarily breaks the light continuity and prevents a portion of the light from reaching at least one detector on the opposite side of the monitoring path. The logic circuit on the detecting arm 235 will note the momentary blockage of light and report it as a delivery event.

The monitoring system is comprised of an emitter arm 240 upon which are located a set number of one or more emitters 242, and a detector arm 250 comprising of one or more detectors 252 and located directly across delivery path 225 from the emitter arm 240. Emitter signals, the total of which comprise light plane 234, are sent from the emitters 242 to the detectors 252 across the delivery path 225, during both monitoring mode and calibration mode. The emitter arms and detector arms are described in more detail in FIGS. 3A and 3B.

FIG. 3A shows the emitter arm portion of the monitoring system. In FIG. 3A, emitting arm 310A transverses along one side of the delivery path in the vending machine. Emitters, 315A, are attached to arm 310A. The horizontal and vertical placement of emitters 315A on arm 310A is determined by the size of the smallest product that crosses the delivery path, and by the type and accuracy of the emitters utilized in the present invention.

The emitters may comprise of an optical monitoring device. The spacing of optical emitters is determined by five factors: emitter size, optical diffusion, ambient light, product size and the reflected light. Emitter size and optical diffusion are fixed at the time of construction; however, ambient and reflective light may vary over the course of use of the emitter. Infrared light may be used to help to reduce these effects; however, it is clearly understood and contemplated by the present invention that other types of light sources can be used, including various lasers or white light sources.

The body 320A of the arm 310A is made of suitable material able to contain the electronic control components 325A necessary to operate the emitter, including, a power source 330A, and logic circuitry 335A. Additionally, holes 340A are provided to securely fasten and adjust the positioning of the arm 310A to the vending machine.

FIG. 3B shows the detector arm portion of the monitoring system. The shape and construction of the detecting arm 350B is related to the shape and construction of the emitting arm 310A. The detecting arm 350B is placed on the same plane, parallel to and across the delivery path from arm 310A (see FIG. 2 for more details). The detectors 355B are arranged so that their vertical spacing and horizontal arrangement mirror the emitter arrangement on arm 310A. Likewise, the body 360B of 350B is constructed of material suitable to contain detection and logic circuitry 365B, attachment holes 370B, and a power source 375B. The choice of the type of detector is directly related to the type of emitter being utilized in the present invention.

FIG. 4 shows the operation of the monitoring system when a customer places an order. Prior to placing an order, the monitoring system is in calibration mode in step 400. Upon placement of the order in step 405, the monitoring system transitions from its steady state calibration mode 400 into its monitoring mode in step 407. Once in monitoring mode, the monitoring system begins cycling each emitter by pulsing the emitter individually in step 410. The monitoring system uses a pulse strength determined from when the system was in the calibration mode.

In step 410 an emitter pulses its signal to the corresponding detector across from the emitter, and the two detectors on either side of the detector. Upon pulsing the light, the detector circuitry determines whether the detectors detected the light from the emitter in step 415. (If the emitter is either the first emitter or the last emitter on the emitter arm, then only the detector across from the emitter and the detector on the non-wall side of the detector is scanned.)

If the detector directly across from the pulsing emitter or the side detectors detects the signal in 415, then the emitter's logic circuit sequences to the next emitter in line and sends a pulse from that emitter in step 420. The emitter's logic circuit continues until after it completes the pulsing of the last detector whereupon, the monitoring system repeats the process, begins again at the first emitter until the detector's logic circuit receives a detect signal and the monitoring system receives a signal to cease monitoring.

If at least one of the three detectors fails to detect a light beam from the emitter during the monitoring cycle, then the logic circuit reports a product delivery to the ordering system in step 425. Once a report of delivery is made to the ordering system, the ordering system returns a signal to the monitoring system to return to steady state calibration mode in step 430. Otherwise, the monitoring system continues to monitor until it receives a return to steady state calibration signal from the ordering system because of a refund, if appropriate.

FIG. 5 shows the steady state calibration mode of the monitoring system. During the steady state calibration mode, the monitoring system is constantly calibrating itself for optimum performance because temperature, humidity, dust, and alignment conditions fluctuate over the course of system usage.

The calibration mode adjusts the light intensity from each emitter as necessary so that each set of three detectors serviced by that emitter receives only enough intensity, plus a small safety margin, to be active in the unblocked condition. This minimizes the adverse effects of reflected light from the emitters and allows for a wider detector aperture (which makes system alignment easier) and reduces the overall power requirements of the system. In step 505, the logic circuit in the monitoring system determines whether an order has been placed. If an order has not been placed, then the monitoring system proceeds to send a series of pulses to the first of the one or more emitters in step 510. Upon sending a pulse, the monitoring system queries the emitter's corresponding detector and each detector on either side of the corresponding detector to determine if those detectors detected the pulsed signal in step 515. If a signal was detected in each of the three detectors then the monitoring circuitry sequences to the next emitter in step 520. The emitters typically have adjustable signal power levels associated with the type of emitter used. The calibration mode will attempt to maintain the power level at the level needed to provide just enough signal, plus a safety margin, such that the corresponding detectors detect the signal. If any one of the three detectors does not detect the pulsed signal from the emitter, then in step 530, the monitoring circuitry determines whether the emitter is operating at its maximum power intensity. If the emitter is not, then the emitter will step increase the signal power level in step 560 and re-send a pulsed signal to the detectors again in step 510. If the power intensity for that emitter is at its maximum intensity, then the detector will send an error message to the monitoring system in step 540. The monitoring system will then follow a precoded routine to shut down the entire vending operation, shut down the monitoring system or rely on prior art ordering systems (the home switch method) in step 550.

FIG. 6 shows a typical detector arm attached to a vending machine. Because of the reflective surfaces 610 in the vending machine, small apertures 620 are used to minimize the reflective light from adjacently reflective surfaces 610. The apertures are narrowed holes located in front of the detectors, 625, on the detector side of sensing system 630. The holes inhibit unwanted reflections from adjacent surfaces by blocking much of the light beams that reflect back to the detector arm at wider angles than the apertures allow.

Apertures 620 keep the majority of the unwanted light from reaching the detection side of the monitoring system. In addition, the detectors 625 have a usable 60-degree horizontal/30 degree vertical reception angle. Light arriving at the detector at angles greater than these is rejected. Additionally, infrared optical detectors contain optical frequency filters, which reject visible light frequencies, but pass the infrared frequencies of interest. Modulation techniques, whereby the detector only responds to certain signal frequencies from the infrared emitters, may also be used to allow the detectors to distinguish between the ambient light and the desired point source light frequency from the emitter.

As mentioned above, product detection may be accomplished by utilizing infrared emitter/detector pairs that can monitor and detect when a signal path is broken. In a typical vending machine's delivery paths, a set of ten infrared emitter/detector pairs are used to cover the delivery path much like a light curtain.

FIG. 7 shows a representative example of a light curtain 730 that may be utilized in the present invention. Typically, nine sets of emitters/detectors are used to cover the main delivery path, while the tenth set is used to cover a gum/mint area. The nine sets that cover the main delivery path implement a technique, which, other than for the first and last emitter, requires that a minimum of three detectors be active for each individual emitter monitor cycle. For those vending machines without a gum or mint section, the tenth emitter may be used for the main delivery area, provided that proper alignment of the ten sets is taken into consideration.

This arrangement is illustrated in FIG. 7, which shows the light beams 710 of interest for each emitter 720 and detector 725. The spacing of the emitter/detector sets are chosen to assure that the smallest size traditional product breaks the path of at least one beam when it crosses the light curtain during delivery. The technique of servicing three detectors for each emitter allows the monitor to read multiple light beams, which further reduces this spacing in the majority of the delivery area. A logic circuit determines whether a light beam has been broken.

In the monitoring system, the infrared emitter/detector sets are controlled by a micro-controller located on the detector arm. During the monitoring mode, it is necessary to monitor each of the emitter/detector sets separately because of the potential for light bleed-over from adjacent emitters. The timing sequence for each set monitor cycle used during the monitoring mode must be fast enough to ensure that the smallest product will be detected by any one of the detectors when the product passes the monitor plane as it falls from the product storage area.

The control software further provides the vending operator an option to revert to home switch operation or to place the vending machine out of service in the event the monitoring system is inoperative. This allows the operator to choose one of two options if the monitoring system is operative: 1. to go out-of-service and thus assure that the customer is cheated since the monitoring system cannot determine proper delivery of a ordered product by home switch operation; or 2. to continue making selections available to the customer under the traditional home switch operation with the risks of non-proper delivery of product that operation implies.

The monitoring system controller printed circuit board uses flash memory to store the firmware. This gives the option to perform firmware updates in the field.

The vending system has several operating options. These may be viewed and programmed by pressing the PRODUCT CONFIG service key on the keypad located on the inside of the vending machine and pressing the down arrow until the appropriate option is reached. The keypad has an associated display device, such as an LED screen or such other typical devices that allow the operator to view the code and results stored within the system.

By depressing the EDIT key, the vendor can choose between “SURE.V ON” or “SURE.V OFF”. “SURE.V OFF” is chosen by the operator only if the monitoring system is not installed or if the operator does not wish to use it at the present time. The remaining options for the PRODUCT CONFIG mode are only visible if “SURE.V ON” is selected and the monitoring system is available.

When “SURE.V ON” is selected, the operator may then choose between “OPT'N SURE.V” or “MUST SURE.V”. If “OPT'N SURE.V” is selected, the vending machine operation reverts to home switch operation if the monitoring system is not operating normally because, for example, of an obstruction or loss of communication. If “MUST SURE.V” is selected by the operator, the vending machine operates only if the monitoring system is available for use for the main delivery area. (The gum and mint area does not affect operation of the main area, unless the programmer decides otherwise.) Otherwise, the vending machine becomes temporarily out-of-service until the blockage or other error is corrected.

When the operator uses the number keys to program “ANTI.JP xx”, the anti-jackpot protection option against unforeseeable cheating of the vending machine's monitoring system is activated. “xx” represents the number of empty conditions that disables the entire delivery system for a time period as programmed and decided by the operator (described below). A empty condition occurs when product delivery is not detected and the customer's money is restored or returned. An “xx” value of “00” disables this anti-jackpot feature.

The assumption of this option is that very few system failures to the vending machine's delivery system occurs. If a significant number of failures, represented by “xx”, do occur then it is assumed that it is because of tampering. Upon reading “xx”, the delivery system is deactivated for a certain amount of time so that money can no longer be refunded because of a vend failure and to discourage a potential thief from attempting to steal either product or money.

In this condition, the vending machine either reverts to home switch operation if “OPT'N SURE.V” is active, or the system deactivates and the vending machine goes out of service if “MUST SURE.V” is active. If in “Must Sure.V”, once the programmed deactivation time has elapsed the system is re-enabled and the count towards “xx” is restarted. The total number of system empty selections, the number of anti-jackpot occurrences, and the date and time of the last occurrence are recorded as noted below.

The operator programs the number of minutes that the vending system remains disabled because of an anti-jackpot occurrence by selecting the “AJP.TMR xxM” option where “xx” is the time in minutes. If “99” is programmed, then the system remains disabled until the main door closes at the end of the next service call. Closing the main door also resets any anti-jackpot time remaining.

Certain system data can be reviewed in the PRODUCT CONFIG mode:

-   -   “SV.EMPTY xx” returns the number of times that credit was         restored or returned because the monitoring system failed to         detect a product delivery.     -   “**.SV xxxx” returns the total number of corrected vends,         viewable by selection. These are the vends, which normally would         not have delivered product if the present invention was not         active.     -   “WO.SV xxxx” returns the number of vends, viewable by selection,         made while the monitoring system was disabled for some reason.

The MACHINE CONFIG list provides additional options related to the present invention. If the operator selects “FAIL=CASH”, the customer's money is automatically returned on any failed vend. If “FAIL=CRDT” is selected, the credit is restored to the vending machine for another selection. The customer may press the coin return to retrieve his money.

The TEST list provides the test screen for the system. If the operator keys in “SV.TST xxx” the following options are provided:

-   “SV.TST OK” indicates that the monitoring system is operating     properly. -   “SV.TST xx” indicates a block in sensing zone 1-9 with 1 being     closest to the glass. “H” indicates the gum & mint is blocked if it     is configured. This number is displayed real-time and beeps as it     changes. This may be used to test the product coverage of the     monitoring system's sensors, although the accuracy is somewhat less     than in actual vend situations because of the data being presented. -   “SV.TST CAL” indicates calibration values that are high. -   “EDIT” may be used to view the calibration values. A high     calibration may be caused by dirt, misalignment of the system     sensors, or a partial blockage of a sensor.

A calibration value of “0” indicates a shorted detector. This normally requires a new detector assembly.

A calibration value of “1” indicates that zone could not be calibrated. It indicates a blocked or damaged sensor.

Calibration values above “A” are abnormal and may require adjustment of the alignment or cleaning of the sensors.

“SV.TST COMM” indicates loss of communication with the monitoring system, and allows the operation to check the harness connections between the vending machine controller and the monitoring system's controller.

Diagnostics Related to the Present Invention:

-   -   “SV.EMPTY nn” shows that selection “nn” was marked as empty         because product delivery was not detected.

-   “SV.TST xx” automatically enters the system test screen as a     diagnostic message if any blocked sensor, communication error, or     calibration error is detected.

-   “AJP.TMR xx.xM” is in the diagnostic list if the anti-jackpot timer     is active. It shows the time remaining.

-   “AJP xxX MN/DY HR.MN” is the total number of times the anti-jackpot     feature occurred plus the date and time of the last occurrence. 

1. A vending method for determining whether a product is delivered, the method comprising: sending a delivery signal to a product delivery system based on a customer ordering event; monitoring a delivery path that the ordered product travels to reach a product receiving location with a monitoring system located along the delivery path to detect when the product passes through the delivery path, the monitoring system optically scanning the delivery path for product transition past the monitoring system using a plurality of light emitters and a corresponding plurality of light detectors by (a) separately activating at least one but fewer than all of the light emitters and (b) for each of the light emitters when that light emitter is activated, monitoring at least two of the light detectors; and determining if the product was delivered to the receiving location.
 2. The method of claim 1 wherein the monitoring further comprises: emitting light from at least one of the light emitters when that at least one light emitter is activated; for each light emitter when activated, monitoring light received at two or more of the light detectors; and determining whether an interruption of light from the at least one activated light emitter to the two or more light detectors has occurred.
 3. The method of claim 2 further comprising: activating each of the light emitters in a sequential series; and activating two or more of the light detectors concurrently with the activated light emitter.
 4. The method of claim 1 wherein the light emitters emit an infrared signal when activated.
 5. The method of claim 1 further comprising: upon failure of a first attempt to deliver the product, attempting redelivery of the product for one or more of a predetermined number of attempts; and providing the customer one or more alternative choices upon failure to deliver the product after the one or more predetermined number of attempts.
 6. The method of claim 5 wherein the step of providing the customer with an alternative choice further comprises: providing the customer alternatively with a first choice to request a second product; and providing the customer alternatively with a second choice to request a refund associated with the customer ordering event.
 7. The method of claim 1 activating the monitoring system to monitor the delivery path in response to the delivery signal.
 8. The method of claim 7 further comprising deactivating the monitoring upon delivery of the product.
 9. The method of claim 3 wherein the plurality of light detectors are each substantially aligned with a corresponding light emitter, the method further comprising: detecting light emitted by each light emitter when activated using a light detector substantially aligned with the activated light emitter and at least one of two light detectors adjacent to the substantially aligned light detector.
 10. The method of claim 5, further comprising: storing data associated with the customer ordering event and redelivery attempts.
 11. A method of enabling verification of the delivery of a ordered product in a vending machine, the method comprising: providing a product delivery system for dispensing a product from a product storage position, along a delivery path to a product delivery position in response to a customer order; providing a monitoring system along the delivery path detecting when the product passes the monitoring system, the monitoring system including a plurality of light emitters and a corresponding plurality of light detectors opposite the light emitters, each light emitter, when activated, emitting light across the delivery path onto a plurality of the light detectors, wherein the emitted light from an activated light emitter is detected, unless interrupted, using two or more of the plurality of light detectors.
 12. The method of claim 11, wherein at least one of the two or more light detectors detects interruption of light emitted by the activated light emitter.
 13. The method of claim 12, wherein the monitoring system includes a logic circuit electronically coupled to the monitoring system, wherein passage of the product along the delivery path is detected by the logic circuit receiving a first logic result when light from the activated light emitter is detected at all of the two or more light detectors and a second logic result when light from the activated light emitter is not detected at at least one of the two or more light detectors.
 14. The method of claim 13, wherein the logic circuit further comprises: an input from the product delivery system; an input from the monitoring system; and an output from a comparison circuit based upon the input from the product delivery system and the input from the monitoring system, the output indicating whether a delivery attempt by the product delivery system resulted in actual delivery of the product.
 15. The method of claim 12, wherein the light emitted by the activated light emitter is infrared light.
 16. The method of claim 12, wherein each of the plurality of light emitters is aligned approximately across from one of the corresponding light detectors.
 17. The method of claim 12, wherein the light emitters and the corresponding light detectors are aligned such that spacing between detectible beams within light emitted by the activated light emitter accounts for a smallest product that passes along the delivery path.
 18. The method of claim 12, wherein power of the light emitted by the activated light emitter is adjusted to compensate for ambient light effects.
 19. The method of claim 12, wherein power of the light emitted by the activated light emitter is adjusted to compensate for reflected light effects.
 20. The method of claim 12, further comprising: providing a data storage device for storing information concerning customer orders.
 21. The method of claim 12, further comprising: providing a logic circuit for determining whether to offer another vend attempt based upon a comparison between a result of the customer order and a predetermined rule.
 22. The method of claim 12, wherein delivery of a set of products is prevented for a predetermined period if a product delivery is not detected in response to the customer order.
 23. The method of claim 20, further comprising: providing a display device wherein an operator can retrieve the information.
 24. A method of monitoring operation of a vending machine comprising: optically scanning a delivery path which a product ordered by a customer travels using an array of emitters on one side of the delivery path and an array of detectors on an other side of the delivery path, wherein a first emitter with the emitter array is actuated alone, a second emitter within the emitter array is actuated alone, and each remaining emitter within the emitter array, if any, is successively actuated alone until all emitters within the emitter array have been actuated, and wherein at least first and second detectors within the detector array are employed to detect light from the first emitter when the first emitter is actuated and to detect light from the second emitter when the second emitter is actuated.
 25. The method of claim 24, wherein, once all emitters within the emitter array have been actuated, actuation of the first, second and any remaining emitters is repeated in cyclic fashion.
 26. The method of claim 25, wherein a period required for all emitters within the emitter array to be actuated at least once is less than a period required for a product to pass through a portion of the delivery path optically scanned using the emitters and detectors.
 27. A method of enabling control based upon product delivery in a vending machine, the method comprising: providing a row of light emitters; providing a row of light detectors opposite the light emitters, each light detector substantially aligned with one of the light emitters, wherein light from each light emitter, when activated, impinges upon a plurality of the light detectors; providing a controller individually and sequentially activating the light emitters in a cyclic manner; and providing logic generating a first logical signal when portions of light emitted by an activated one of the light emitters are detected at all of two or more of the light detectors and a second logical signal when at least one portion of the light emitted by the activated light emitter is not detected at at least one of the two or more light detectors, wherein the controller is adapted to operate in a calibration mode and in a monitoring mode, and wherein the controller is adapted to operate in the calibration mode prior to receipt of a customer order and switch to the monitoring mode upon receipt of the customer order.
 28. A method of enabling control based upon product delivery in a vending machine, the method comprising: providing a row of light emitters; providing a row of light detectors opposite the light emitters, each light detector substantially aligned with one of the light emitters, wherein light from each light emitter, when activated, impinges upon a plurality of the light detectors; providing a controller individually and sequentially activating the light emitters in a cyclic manner; and providing logic generating a first logical signal when portions of light emitted by an activated one of the light emitters are detected at all of two or more of the light detectors and a second logical signal when at least one portion of the light emitted by the activated light emitter is not detected at at least one of the two or more light detectors. wherein the controller is adapted to operate in a calibration mode and in a monitoring mode, and wherein the controller is adapted to operate in the monitoring mode prior to detection of product delivery and switch to the calibration mode after product delivery is detected. 